Advances in electronics have resulted in an increasing number of functions and capabilities being realized by semiconductor devices, for example, integrated circuits (ICs). To provide those functions and capabilities, semiconductor devices, such as ICs, continue to include an increasing number of transistors.
To reduce cost and yet meet the specifications for more functions and capabilities, semiconductor technology has continued to drive the trend towards higher device density and smaller device geometries. Those trends have affected the characteristics of semiconductor devices. For example, certain semiconductor devices tend to have different characteristics as they near the end of their lives than they do near the beginning of their lives.